Abstract

Annealed metallic bilayers consisting of Cu/Al/SiO2 are studied from the perspective of providing both surface passivation and diffusion barrier/adhesion promoter function for advanced copper based metallization. Upon annealing this bilayer film at 400 °C or higher, enough Al dissolves into the Cu to provide substantial oxidation resistance at the coppersurface. The resistivity of these annealedfilms is approximately 4.5 μΩ cm. Compared to films of pure copper, these bilayer films are much more adherent to SiO2 and much more stable (both morphology and diffusion) on SiO2.